Priming composition



dangers to health Patented Nov. 29, 1932 EDMUND VON HERZ, OFCOLOGNE-DELLBRUCK, AND HANS RATHSBURG, OF FURTH, GER- MANY, ASSIGNORS,BY MESNE ASSIGNMENTS, TO REMINGTON ARMS COMPANY, IN- CORPORATED, OF NEWYORK, N. Y., A CORPORATION OF DELAWARE ranmwe 'comrosrrron No Drawing.Application filed February 20,- 1930, Serial $0. 430,138, and in GreatBritain March 8, 1929.

This invention relates to priming compositions for aminunition andparticularly to the class of priming compositions'which arenoncorrosive, that is, which do not leave in the bore of the firearm aresidue which upon subsequent exposure to a humid atmosphere causescorrosion. The present application is a continuation-in-part of ourco-pending application Serial No. 352,893, filed April 5, 1929.

The function of a priming composition in a cartridge is to provide aflame of suflicient intensity of heat to effectively ignite thepropellant powder, the priming composition itself being ignited bytheoblow of thefiring pin upon the riming mixture container. Untilcomparatively recently substantially all commercially successful primingcompositions have included, as their chief ingredients, mercuryfulminate, potassium chlorate, and a fuel to be burned withthe oxygenlib-' 'erated from the potassium chlorate; the principal fuels beingantimony sulphide and/or lead sulphocyanate. Mercury fulminate alonedoesn'ot function well as a primer for the reason that it explodes withtoo great violence when struck a blow, and produces very little flameand heat. Its function in prim ing compositions is to initiate areaction between the oxidizer and the'fuel, such reaction furnishing thehot flame of substantial liength and duration which ignites the pow-Both mercury fulmina-te and potassium chlorate are objectionable inpriming mix tures. The potassium chlorate breaks down into a highlyhygroscopic potassium chloride, which is the a ent responsible for aftercorrosion. It has een found possible, by a careful selection andaccurate proportion of ingredients, to replace potassium chlorate withcertain other oxidizers which do, not leave corrosive residues. Mercuryfulminate, however has remained a standard sensitizer or combustioninitiator for practically all ammunition rimers It isobjectionable notonly byn ason of its high and in-.\ creasing cost but also on account ofits highly poisonouscharacter with the consequent the workmen-engaged inhandling, mixing and loading it into cartridge shells and primer cups.Furthermore, mercury fulminate tends to react' with many materials whichotherwise are desirable primer mixture ingredients, thus greatlylimiting the number of available oxidizers and fuels; It alsoamalgamates readily with many metals, such as the zinc in brass,necessitating the use of expensive copper or nickel plated primer cups.The elimination of dangerous, poisonous and troublesome mercuryfulminate has, for these reasons, been the ideal of am-c mun1t1onmanufacturers for a great many yea'rs.

In the United States Patent No. 1,443,328

to Edmund Von Herz there is described the production of the normal leadsalt of styphnic I acid, commonly called lead trinitroresorcimate; andthe use of this substance generally as a priming mixture ingredient.Experiment and test have indicated the desirability i of a sensitizer insuch mixtures, and the pending application of J. E. Burns, Serial No.177 ,848, filed March 23,1927, discloses mixtures including leadtrinitrore'sorcinate with substantial amounts of mercury fulminate. Inthese prior disclosures, however, as well as in all prior primermixtures of any kind,

the sensitizing ingredient has been present in such proportions as toconstitute a sub- -which does not have the disadvantages of mercuryfulminate.

The sensitizing agent utilized in the-present invention is selected fromthe class of compounds known as tetracenes, said compounds beingdescrihed in the British patent to Rathsburg, No. 201,009 of June 30,1922. In said co-pending application, Serial No. 352,893, filed April 5,1929, we have, dis-- ,particularly the health of closed our discoverythat a tetracene, for

guanylnitrosaminoguanyltetracene to secure exampleguanylnitrosaminoguanyltetracene (C H ON possesses suchvalue as asensitizer for priming mixtures that itmay be used in extremely smallquantities, even to the surprisingly small amount of .5 of one per cent.In connection with the furtherance of our experiments it has been foundthat the small amount of 0.5% of guanylnitrosaminoguanyltetracene is insensitizing eifect equivalent to that of a very much larger amount ofmercury fulminate. More specifically, 0.5% ofguanylnitrosaminoguanyltetracene has been foundto produce the sameresult as about 18% of mercury fulminate and 1% ofguanylnitrosaminoguanyltetracene has been found substantially equivalentto 30% of mercury fulminate. While 0.5% is a sufficient quantity ofproper ignition of most powders, it is desirable in preparing largequantities of priming mixture to use a somewhat greater amount. This isdone to insure that every part of the batch will contain a minimum of0.5%. In commercial practice priming mixture is prepared in lots of 5 to10 pounds While the individual charge for each cartridge is from .25grain to about 1 grain. Obviously, it is very difiicult to secure such aperfectly uniform distribution of an ingredient present in the amount ofonly one-half of 1% that each individual charge would contain no lessthan this amount, and the difiiculty is augmented by the light, fluify,voluminous character of guanylnitrosaminoguanyltetracene. For thisreason, in actual practice 1.5% or 2% or for special types of mixturesas much as 4% is'ordinarily used. 0.5% has been definitely determined asthe minimum which will consistently effect satisfactory priming.

The other ingredients of the mixture may include leadtrinitroresorcinate, one or more non-corrosive oxidizers, such as bariumnitrate and/or lead peroxide, and one or more fuels, preferably of ahard and gritty nature, such as antimony sulphide and/or calciumsilicide.

A typically successful mixture is as follows:

' P Guanylnitrosaminoguanyltetracene- 0. Lead trinitroresorcinate 20 +45Barium nitrate 30 ,5O

Antimony sulphide and/or other fuel, as for example, calcium sili- Leadperoxide .7 12

Antimony sulphide 0 5 Calcium silicide 6 12- Glass 1 7 0 3 It will benoted that each' of the above formulas includesguanylnitrosaminoguanyltetracene in an extremely small amount, thesepercentages of guanylnitrosaminoguanyltetracene as above stated beingequivalent in their effects to 18% to 30% of mercury fulminate.

tiveness of guanylnitrosaminoguanyltetracene to, shock and friction issubstantially the same as. that of mercur fulmi'nate- .Theirsensitiveness is so near t e same that there is a difierence of opinionas to whichis really the more sensitive. The present invention isbelieved to comprise the first discovery of a priming mixture in which afundamental and essential ingredient is present in an amount of thegeneral order of 1%, and for this reason, the appended claims are to bebroadly construed.

What is claimed is: v

1. A priming mixture containing guanylnitrosaminoguanyltetracene in anamount not greater than 4%.

2. A priming mixture containing between 0.5% and 4%guanylnitrosaminoguanyltetracene.

x 3. A priming mixture containing a non- This discovery is rendered evenmore remarkable by the fact that the semi-- corrosive oxidizer, a fuel,and'not more than 4% of guanylnitrosaminoguanyltetracene.

.4. A priming mixture containing lead -tri-' nitroresorcinate, and 9.5%to 4% of guanylnitrosaminoguanyltetracene.

5. A priming mixture containing lead tri- .6. A priming mixturecontaining lead trinitroresorcinate, barium nitrate, antimony sulphide,and not more than 4% of guanylnitrosaminoguanyltetracene.

7. A priming mixture containing lead trinitroresorcinate a non-corrosiveoxidizer, antimony .sulphlde, calcium silicide, and not more than 4% ofguanylnitrosaminoguanyltetracene.

8. A priming mixture containing lead trinitroresorcinate, bariumnitrate, antimony sulphide, calcium silicide, and not more than 4% ofguanylnitrosaminoguanyltetracene.

9. A priming mixture contalni ng approximately:

- Per cent Guanylnitrosaminoguanyltetracene-; 0. 5-. 2 Leadtrinitroresorcinat 35 -40 Barium nitrate l 35 42 Lead peroxide 7 12Antimony sul hide 0 5 Calcium silici e 6 -12 Glass 0 3 10. A primingmixture containing barium nitrate, lead peroxide, antimony sulphide,

calcium silicide, and a quantity of guanylnitrosaminoguanyltetracene notgreater than 47. I 0 EDMUND VON HERZ. HANS RATHSBURG.

